Portion of a shoe midsole



FIG. 1 is a front perspective view of a portion of a shoe midsole showing my new design;

FIG. 2 is a rear perspective view thereof; and,

FIG. 3 is a side elevational view of one side thereof.

The uneven broken lines immediately adjacent to the shaded area represent unclaimed boundaries of the design. The unshaded areas within the uneven broken lines are for illustrative purposes only and form no part of the claimed design. The uneven broken line showing of the shoe upper and the remainder of the shoe sole is for illustrative purposes only and forms no part of the claimed design. 

The ornamental design for a portion of a shoe midsole, as shown and described. 